What Can We Do?
The story of human impacts on marine nursery areas is a complex one involving not only a large number of diverse impacts, and drivers behind those impacts, acting simultaneously, but also cumulative effects over time. Unfortunately, we often respond to such impacts on natural systems only after the damage is done – and our response is typically too little, too late. Much like the fable of the golden goose, we may come to regret the destruction of marine nurseries once the ecological services are lost.
A. Integrate Land Use Management: Integrated management of watersheds, land use planning, and impact assessment are a keys to protecting nursery sites. Complex problems require comprehensive solutions. For this reason, tackling the issues of loss and degradation of marine nurseries by addressing single threats to these environments is not the most effective way to address the problem. A holistic look at how we affect marine nurseries, identify the key threats, and implement management that is integrated across all sector is needed. A large part of this effort must be devoted to overcoming conflict among stakeholders with competing interests. Effective management of these crucial areas means coordinated pollution controls, development restrictions, fisheries management, and scientific research. To be truly holistic, integrated management of marine nursery areas also requires complementary watershed management and land use planning – to ensure that negative impacts do not reach nursery areas from afar181 182 183.
To fully understand and quantify the trade-offs to be made when coastal development, environmental degradation through waste discharge, or exploitation of nursery areas occurs, environmental impact studies should take into account the full value of these ecologically critical areas184 185. The evaluations should also consider the cumulative impacts in the context of current and future developments in order to avoid the tyranny of small decisions, instead of assessing proposals in isolation186. Zoning plans and permitting procedures for development that is potentially environmentally harmful should take into account the costs of losing the ecosystem processes and services that these areas provide187 188.
B. Create Marine Protected Areas.When marine areas have been identified as particularly important marine nurseries, necessary steps should be taken to conserve these habitats and the species within them through marine protected areas189 190 191 192 193. Such protected areas may be small fisheries reserves in which resource extraction is prohibited194 195 196, or they may occur in the context of larger multiple use areas197. Increasingly, marine protected areas are being established in networks, in order to safeguard the most critical areas of the marine environment such as marine nursery areas throughout a geographically large area198 199.
In order for marine protected areas to succeed in meeting the objectives of conserving habitats and protecting fisheries and biodiversity, management of these areas should address, if possible, all the proximate threats to marine and coastal areas200 201. In nursery habitats, the threats are multiple and cumulative over time. Thus protected areas that address only one of these threats in a piecemeal fashion will usually fail to conserve the ecosystem or habitats and the services they provide (3, 202. And it must be recognized that MPAs are not a panacea, and the context in which these islands of protection sit must be adequately managed as well.
C. Manage fisheries on an ecosystem basis. Historically, most marine fisheries were managed on a stock by stock, or fishery by fishery basis. Increasingly, people have begun to realize this single species approach is inefficient in conserving the complex ecological processes in marine and coastal systems. Among fisheries management agencies and conservationists alike, a new push is now on for ecosystem-based fisheries management – management that looks at multi-species interactions and the entire chain of habitats these linked organisms need in order to survive and reproduce. The protection of nursery habitat must figure very prominently in ecosystem-based fisheries management203. As a result of this rather new approach, conservationists and protected area managers have begun to work with fisheries biologists and managers – spanning a gap between disciplines204. Genetically unique stocks should also be protected205.
Protecting key habitats like nursery areas is a necessary component of an ecosystem-based approach. However, there are criticisms that are leveled at the way this is done in the context of current fisheries management, in the U.S. and elsewhere. For instance, the designation of Essential Fish Habitat, which includes nursery areas, is done for federally managed species in the U.S., but some fisheries biologists have argued that it is an inefficient use of management resources (Jim Cowan, pers. Comm.).
D. Use Areas Sustainably. Even when people are made aware of the importance of marine nurseries, they still may not be able to stop of the kinds of activities that destroy or degrade these areas, unless alternative resources or livelihoods are made available to them. For instance, boat-builders of the coastal and island communities of East Africa have little choice but to remove mangrove from key nursery habitats, which, incidentally, support the very fisheries upon which their boat-building industry is based206. Few alternatives materials for boat building exist, except for cases in which conservation projects have expressly built in alternatives and training on how to use alternative. In areas in which resource extraction is moving beyond ecologically sustainable limits, or in which the removal of the resource causes major physical changes to the habitat, the search for alternatives is particularly crucial207 208.
However, it is not only local, small scale actors who are driven to unsustainable use. Large scale industrial fishing drives much destruction and degradation of nursery areas209, and demand for fisheries products fuels the growth of fisheries and aquaculture that is both ecologically unsustainable and socially inequitable.
E. Control Pollution.Pollution of marine nursery areas is a very significant cause of loss of this important ecosystem service in much of the world. The over-fertilization of nearshore waters via land-based sources of pollutants and via waste disposal into rivers and coastal zones is a particularly acute problem. One method of mitigation is to conserve, reconstruct, or construct new wetlands that act as filters of these pollutants before such compounds enter the coastal environment210. Another is to encourage land use practices such as buffer strips in agriculture and forestry to prevent the run-off of fertilizers, sediments, etc.211. It would be prudent also to invest in research and support agricultural production techniques that eliminate or reduce the use of pesticides, herbicides, and nematocides in the first place. As for hydrocarbons and other toxins, the way that municipal waste and storm run-off is treated should be improved212 213. Dredging operations should be assessed for the degree to which they may release pollutants into the water column, ultimately affecting critical nursery areas214. In some areas, there will be a need to have contingency plans along with the appropriate equipment and trained staff to deal with the unfortunate event of an oil spill or hazardous materials spill.
F. Maintain connections. Access to and from nursery areas is critically important, as mentioned earlier. Coastal constructions that interfere with this access can render key nursery areas fallow215 216. Human activities can also impede the linkages among nursery areas and other sites by degrading the environments that connect such places217. For example, ocean dumping sites located in the migratory corridors between nursery and adult feeding habitats of leatherback turtles may have a significant role in recruitment and population dynamics218. Thus to conserve such sites is not enough, we must also work to conserve access to and from these places. Since many marine species have larval dispersal and experience high mortality during early life stages, significant effort should be directed towards uncovering bottlenecks where the connections between nursery and other important habitats are at risk.
G. Restore key areas. Some nursery habitats such as mangrove forests and marshes can, in theory, be restored once destroyed. Such restoration is risky, however, since it has yet to be shown that the full range of ecosystem services can be supported by artificially reconstructed wetlands219 220 221. Restoration is also difficult when the baselines have shifted and the ecological character and condition of the wider area has changed. Furthermore, the costs of such restoration can be enormous, as recent Congressional appropriation of billions of dollars for the restoration of the cord grass system attests222. As a rule of thumb, most ecologists and policy-makers would agree that it makes more sense to protect it than to lose it and then spend time and money trying to restore it223.
H. Promote further research. Further research on ecosystem function, sustainable yields, and economic valuation is needed. We are undeniably a long way from understanding marine systems generally, and marine nursery areas in particular224 225. Because of the importance of these areas for the biosphere and for humankind, it behooves us to target research towards fundamental questions on how these ecosystems function, what our impact on them really is, and what can be done to effectively mitigate against the loss and degradation of these habitats226. Research protocols and priorities should be set with the aim of integrating research findings to develop comprehensive views of the ecological requirements of marine species227.
In order to convince policy-makers and the public that the protection of marine nurseries is of paramount importance, we must also invest in better economic valuations of these areas, so as to better understand the trade-off that are made when development threatens the nursery areas and the ecological services they provide.
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